1. Field of the Invention
The present invention relates generally to a Digital Video Broadcasting-Handheld (DVB-H) service, and in particular, to a method and system for quickly setting a new channel when a DVB-H terminal initially sets a channel or changes the channel.
2. Description of the Related Art
In general, digital broadcasting is a broadcasting service for providing high image quality, high sound quality, and a high-level service to users by replacing conventional analog broadcasting. There are various kinds of digital broadcasting, for example, Digital Multimedia Broadcasting (DMB), Digital Audio Broadcasting (DAB), Digital Video Broadcasting (DVB), MediaFLO (Forward Link Only), and DVB-Handheld (DVB-H).
A DVB-H service uses an Internet Protocol Data Casting (IPDC) method of broadcasting broadcast data by compressing the broadcast data containing Audio/Video (A/V) data in a predetermined packet unit basis as in a wired/wireless Internet system. In order to reduce the power consumption of a DVB-H terminal, a DVB-H server collects data to be transmitted for a predetermined time interval as burst data and transmits the burst data at every predetermined time interval without continuously transmitting the data.
FIG. 1 illustrates a time slicing transmission method of a DVB-H service. FIG. 1 shows timing slicing of an A/V stream 10 corresponding to a single A/V channel, wherein the timing slicing is achieved in a period of time between t0 and t1. Referring to a transport stream 20, a DVB-H server collects data corresponding to the time between t0 and t1 from among the A/V stream 10 for a short burst duration beginning from the time point t1, i.e. a time slice, and transmits the collected data. D0 denotes the transmitted burst data. The DVB-H server stops transmitting the A/V stream 10 for a time duration from when the time slice corresponding to D0 ends to when a subsequent time slice starts. The time duration is referred to as off-time. A digital broadcasting receiver of a DVB-H terminal is activated during only the time slice and deactivated during the other duration, i.e. the duration in which the A/V stream 10 is not transmitted.
As illustrated in FIG. 2 according to the prior art, a transport stream 40 with respect to an A/V stream 30 corresponding to a single channel service includes a single elementary stream, and the A/V stream 30 is transmitted by means of the single elementary stream. That is, an A/V packet is only once transmitted via a DVB-H channel.
As described above, according to the conventional time slicing transmission method, when a single service, i.e. a single A/V stream, is considered, if off-time is decreased, an average time taken from when a DVB-H terminal decides to receive the single A/V stream to when burst data of the single A/V stream is actually received is reduced, whereas current consumption in a digital broadcasting receiver of the DVB-H terminal increases. On the contrary, if the off-time is increased, the current consumption in the digital broadcasting receiver decreases, whereas the average time taken from when the DVB-H terminal decides to receive the single A/V stream to when the burst data of the single A/V stream is actually received is increased. The decision to receive the single A/V stream can be achieved by means of a channel change to a channel corresponding to the single service.
As described above, there is a trade-off relation ship between power consumption in a DVB-H terminal and an average time taken to receive actual burst data. In other words, when the DVB-H terminal sets a new DVB-H service channel, if the time-off is decreased in order to reduce the time taken to set a channel, power consumption increases, and if the time-off is increased in order to reduce power consumption, a channel setting time increases.